Sport is full of comeback stories which defy logic. That's why America's Cup doubt is now looming large. Could Oracle join the list of sporting miracles in San Francisco? How might the story end?

America's Cup, 2013: slapped with a two-race penalty before the regatta even began, Oracle trailed 8-1 in the 17-race series. Team New Zealand needed just one more win but ...

Other great sports comebacks

2005, US Open, Michael Campbell, golf

Michael Campbell was hopelessly out of form coming to Pinehurst, missing his first five cuts of the year, yet somehow found a way to play four great rounds, and beat Tiger Woods et al to claim his first major championship.

2005, Champions League football final, Liverpool

When AC Milan led Liverpool 3-0, and it looked bleak for the Scousers. No worries. Liverpool tied it up with three goals in six minutes, then won a penalty shootout.

2012, Ryder Cup, US vs Europe, golf

The Miracle at Medinah. Stating the final day, the US led 10-6, Europe needed 8 points from 12 matches to retain the Cup, yet did it with matches to spare. Wild-eyed English golfer Ian Poulter set the tone with a run of five birdies, with until-then out-of-form German Martin Kaymer sealing it.

1972, Olympic Games, running, Lasse Viren

Flying Finn Viren tripped and fell In the 10000m final and lost at least 25m. He leapt to his feet, caught the field within a lap, looped around his stunned rivals, and carried on to claim gold.

1993, Women's Wimbledon final, tennis, Steffi Graf

Jana Novotna led Steffi Graf 6-7 6-1 4-1 and at 40-30 in the sixth game of the deciding set had a service point for a 5-1 lead. Within 10 minutes Graf had somehow won 7-6,1-6, 6-4.

2002, Winter Olympics, speed skating, Steven Bradbury

Bradbury had no chance of winning speed skating's 1000m until all of his opponents fell in a last corner pile-up, and he swept past all the trouble to Australia's first Winter Olympic gold.

2004, Major League Baseball, Boston Red Sox

When the Boston Red Sox won the World Series in 2004, it ended an 86 year curse. Down 3-0 against the New York Yankees in the American League final, and down 4-3 in the bottom of the 9th in game four, they found a way to win that game, then the next three. They then beat the St Louis Cardinals in the World Series.

1983, Melbourne Cup, horse racing, Kiwi

An outsider Kiwi was at 10/1. With 500m to run, he was second to last. His storming run through the field made his rivals look like they were walking, as Kiwi won by just over a length. It was one of the most memorable wins in the glittering history of the great race.